Respuesta :
Any time you have a fraction within an equation, multiply the entire equation by the denominator to clear the fraction. Since the lead term is negative, we can multiply that away as well
(-14) (0=-1/14x²+4x+5) [now distribute]
0=x²-56x+70 [try to factor into binomials first]
Since 70 only has prime factors of 2·5·7, there is no combination which equals (-56). Use the quadratic formula, or complete the square. I'll use quadratic:
x=-b+/-√(b²-4ac)
2a
a=1, b=(-56), c=70
x= -(-56)+/- √((-56)²-4(1)(70)
2(1)
x= 56+/- √(3136-280)
2
x=56+/-√(2856)
2
x=56+/-√(2³·3·119)
2
x=56+/-2√(714)
2
x=28+√714; x=28-√714
(-14) (0=-1/14x²+4x+5) [now distribute]
0=x²-56x+70 [try to factor into binomials first]
Since 70 only has prime factors of 2·5·7, there is no combination which equals (-56). Use the quadratic formula, or complete the square. I'll use quadratic:
x=-b+/-√(b²-4ac)
2a
a=1, b=(-56), c=70
x= -(-56)+/- √((-56)²-4(1)(70)
2(1)
x= 56+/- √(3136-280)
2
x=56+/-√(2856)
2
x=56+/-√(2³·3·119)
2
x=56+/-2√(714)
2
x=28+√714; x=28-√714
